Sliding clamp for electric welding apparatus



(No Model.) '2 SheetsSheet 1. H. LEMP. SLIDING CLAMP FOR ELECTRIC WELDING APPARATUS.

No. 428,616. Patenfed May 27, 1890,

F 125KB.

a I AA I V I ATTORNEY 2 Sheets-Sheet 2.

(No Model.)

H. LEMP. SLIDING CLAMP FOR ELECTRIC WELDING APPARATUS. No. 428,616. -Patented May 27, 1890.,

1 J 8" f x Fig.5

FiqE.

WITNESSES: INVENTOR Ji'ermwm Lamp ATTORNEY UNITED STATES PATENT OFFICE.

HERMANN LEMP, OF LYNN, MASSACHUSETTS, ASSIGNOR TO THE THOMSON ELECTRIC IVELDING COMPANY, OF MAINE.

SLIDING CLAMP FOR ELECTRIC W ELDING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 428,616, dated May 27, 1890.

Application filed August 8, 1889. Serial No. 320,182. (No model.)

To all whom it may concern: cross-section through a slide and rest con- Be it known that I, HERMANN LEMP,a citistrueted in accordance with my invention. zen of the United States, and a resident of Fig. 4 is an end elevation, and Fig. 5 a side Lynn, in the county of Essex and State of elevation, ofa preferred construction. Fig.6 5 Massachusetts, haveinvented certain new and is a side elevation and partial section showuseful Sliding Clamps for Velding Appaing the application of part of .my invention to ratus, of which the following is a specificaa modified construction. t1011- Referring to Figs. 1 and 2, M indicates the My invention relates to that part of an eleeclamp-slide, and P the bed or rest on which 1o trio welding or metal-working apparatus it moves in electrical contact with such bed. which holds the piece or pieces of metal to be The clamp-slide M bears the clamping devices heated by the electric current, and which is and the piece of metal which is to be heated made movable for the purpose of pressing the by the current, and the bed P is in the path piece held toward another piece, or for other of the electric current flowing to the slide. 15 purpose, as in forging, upsetting, riveting, or In order to preserve a good electrical connecother operations. In this class of apparatus, tion between the bed and slide, clamps O 0 especially when used for welding operations, are ordinarily employed for the purpose of the clamp-slide must not only be mounted so exerting a downward pressure on the clampthat electric current may pass freely between slide. 7 20 it and its supporting-bed, but it must also be T is the table by which the parts are caraccurately guided. ried. As will be seen, provision is also made The object of my invention is to overcome for holding the clamp-slide against lateral certain practical difficulties found to exist in movement. In order to obtain the highest the use of the present method of mounting conductivity possible, it is the practice to z 5 and guiding clamp-slides, while at the same make the slides and clamps of copper, which time permitting the slide to be made without not only would expand considerably with an requiring a high grade of skilled labor; and increase of temperature, but also readily conto this end my invention consists in the peducts heat from the clamp holding the work. culiar constructions and details, to be here- With the construction illustrated in Figs. 3o inafter more fully described in connection 1 and 2, if the clamp-slide be loosely fitted, with the accompanying drawings, and then current will not pass from the clamp bed or specified in the claims. seat to such slide with sufficient freedom, and In electric welding and similar apparatus if it be tightly fitted the clamp-slide may not the large volume and the low electro-motive be moved freely to follow upareadily'fusible 35 force of the heating electric current make it material in the operation of welding. Moreneeessary not only that the supporting-posts over, it will frequently happen that after the which carry the work and convey current first or second weld the clamp-slidewillwedge thereto should be of some good conductor, in its guides and cannot be used further until but also that the clamp-slide and its bed cooled off. The construction illustrated in 0 40 should be of low resistance. It is also of the Fig. 1 is also a very expensive one and regrcatest importance, especially with small quires skillful labor. In order to overcome work or with work which fuses readily or bethese objections, I form the slide and bed so comes very soft at welding temperature, that that the slide shall rest thereon by a V-shaped the clamp-slide should move with freedom, bearing, as indicated in Fig. 3. lheV-shaped 4 5 and further that it should be guided or held groove in the bed-plate P may be readily against lateral movement, in order that the made by the use of any ordinary planer. parts of the work may be kept in line. One or more bolts or rods B extend down In the accompanying drawings, Figures 1 from the clamp-slide through the bed or rest and 2 are cross-sections through clamp-slides P, and carry beneath the table T the rollers 50 and rests or beds for the same, and show con- R R, which run upon the bottom'of the table structions heretofore employed. Fig. 3 is a and are supported by one or more flat springs S, carried by rod B. The springs S serve to exert a downward pressure upon the clampslide, thus holding it firmly to its seat and making good connection with the bed or rest P. In this construction not only is there a large contact-surface which will perfect itself by wear, but moreover any expansion in the clamp-slide or rest therefor will only result in lifting the movable part in a direction opposite to the spring-pressure, while such expansion will be taken up by the spring S. It is also obvious that wedging of the movable clamp-slide in the stationary rest cannot take place and that good contact will be maintained underall conditions. The slide may be moved in its seat longitudinally by any of the devices employed in the art.

In delicate work it is necessary that the slide should move with the greatest freedom. In order to permit this, while at the same time not interfering with the free conduction of electricity from the rest to the slide, I interpose between the slide and its rest a number of copper rollers or balls R as indicated in Figs. 4; and 5. The downward pressure is in this instance obtained by means of springs S S, connected to rods which extend longitudinally from the clamp'slide M. The springs may be applied, as indicated, at an angle, so as to assist in moving the clampslide with the work toward the opposite clamp, and thereby to re-enforce the action of the spring S acting in a direct horizontal line or line of movement of the clamp.

By means of the rollers or balls of copper between the c1amp-slidc and its seat I find that an electric current of great volume may be passed from the seat or bed P to the slide without any undue heating and without interfering with the free movement of the slide.

In Fig. (5 I have illustrated the application of the copper rollers or balls to a slide and bed or seat having flat opposing surfaces. The spring S, which holds the slide down, has interposed between it and the bed P frictionrolls R, as indicated. As the rolls R, Figs. 3 and 6, are not necessarily in the path of the electric current, they maybe made of iron or other material. The rolls R are of copper or other good conducting material.

\Vhile I have shown the rolls in Figs. 4 and 5 as consisting of rods, I do not limit myself to the employment of such form of roll, al-

though I prefer to use it, since a larger conducting mass of rolls may be obtained in a given space between the slide and the rest.

\Vhat I claim as my invention is 1. In an electric welding or metal-working apparatus, a slide supported on its rest or bed by a V-shaped bearing, said slide and bed being included .in an electric circuit to the work, so that the electric current will pass through the bearing.

2. The combination, in an electric welding or metal-working apparatus, with a clamp slide having a V-shaped bearing or bearings, of a downward-pressure spring, as and for the purpose described.

3. The combination, in an electric welding or metal-working apparatus, of a clamp-slide, a fixed bearing therefor, and interposed conducting-rolls of copper or other good conducting material, as and for the purpose described.

at. The combination, with the movable slide, in an electric welding or metal-working apparatus, of a downward-pressure spring carried beneath the slide and interposed rolls between such spring and the bed or table.

5. In an electric welding apparatus, a conducting-slide having a mechanical bearing and electrical contact or connection through .V-shaped bearing-surfaces, as and for the purpose described.

6. The combination, in an electric welding or metal-workin apparatus, with a V-shaped conducting-slide, of depending rod or rods and springs carried thereby for imparting a downward pressure.

7. The combination, in an electric welding and metal-working apparatus, of a conducting-slide supported on a seat or bed by a V- shaped bearing and having a rod or rods extending through such rest or bed for con nection with springs for holding the slide in contact with the bed.

8. The combination, with the conductingslide, in an electric welding or metal-working apparatus, of a conducting slide-rest on which the slide bears by a V-shaped bearing and interposed conductingcylindrical rods of copper, as and for the purpose described.

9. The combination, with a conductingslide, in an electric welding or metal-working apparatus, of a V-shaped bearing for said slide and interposed roller-contacts, as and for the purpose described.

Signed at Lynn,in the countyof Essex and State of Massachusetts, this 3d day of July,

IIERIIANN LEMP. Witnesses:

JOHN TREGONING, EINAR ROSMUSSER. 

